650 BULLETIN 2 3, UNITED STATES NATIONAL MUSEUM 



The first winter plumage is acquired by a partial postjuvenal molt, 

 beginning early in July, which involves the contour plumage and the 

 wing coverts, but not the rest of the wings or the tail. The sexes are 

 recognizable in this plumage. Dr. Dwight describes the young male 

 as "above, cinereous gray, browner on the back, the crown yellow- 

 tinged and sometimes flecked with black ; wing coverts uniform with 

 the back. Below, including supraloral line lemon-yellow, the orbital 

 ring paler, a narrow 'necklace' of small black spots on the jugulum 

 the black extending to the auriculars and lores, slightly veiled by 

 overlapping yellow edges ; the crissum dull white." The first w^inter 

 female plumage "is a little paler than that of the male without black 

 on the crown which is brownish in contrast to the back and the 'neck- 

 lace' consists of obscure grayish lines." 



The first nuptial plumage is acquired mainly by wear, but there is 

 a limited prenuptial molt about the head, chin, and throat. Young 

 birds are now like the adults, except for the worn wings and tail, 

 which have been carried over from the ju venal plumage. Adults have 

 a complete postnuptial molt in July. The adult winter plumage of 

 the male is "quite different from first winter dress, the black 'necklace' 

 being of heavy streaks and the black area on the lores and crown 

 larger ; black feathers with broad grayish edgings are assumed on the 

 crown, and the wing edgings are apt to be grayer and bluish instead 

 of greenish." In the female, "the adult winter plumage differs slightly 

 it any from the first winter ; it has a bluer gray tint on the back and 

 the crown is yellow-tinged rather than brown." 



The adult nuptial plumage in both sexes is acquired mainly by 

 wear, with possibly some new growth. The female is always duller 

 in coloration than the male, but she usually shows some traces of the 

 "necklace." 



Food.—Ora W. Knight (1908) says of the food of the Canada war- 

 bler : "They eat moths, flies, beetles, grubs, caterpillars of the smooth, 

 hairless type such as canker worms, the eggs of insects, spiders, mos- 

 quitoes and similar insects." Prof. Aughey (1878) found five locusts 

 and 29 other insects in a stomach examined in Nebraska. The items 

 mentioned above as the food of the young are doubtless also included 

 in the food of the adults. Of three specimens examined by F. H. 

 King (1883) in Wisconsin, "two had eaten flies; one, a hymenopterous 

 insect; one, beetles; and one larvae." Although the Canada warbler 

 obtains most of its food on the branches and foliage of trees, as well as 

 on the ground, it feeds largely on the wing, catching its insect prey in 

 the air. It is one of the most expert of the warblers in this pursuit, 

 hence it was formerly called the Canada flycatching warbler, or Can- 

 ada flycatcher. 



Behavior.— Gerald Thayer wrote to Dr. Chapman (1907) : "The 

 Canadian is a sprightly, wide-awake, fly-snapping Warbler, vivid in 



